Method and system for efficient and accurate filtering and interpolation
AssigneeSilicon Valley Group, Inc.
InventorRoberto B. Wiener
Life of this patent
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Abstract
The present invention is directed to efficient and accurate filtering and interpolation techniques. Methods of the present invention reduce the number of required operations and reduce computational errors in the filtering and interpolation of discrete input signals.
Claims40
A method of reducing the number of operations required to interpolate a discrete rectangular input signal having a first sampling rate into a discrete output signal having a second sampling rate, the method comprising the steps of:
- (a) selecting a plurality of input signal values from the input signal, wherein each selected input signal value corresponds to a particular time increment at the first sampling rate;
- and
- (b) generating, at a time increment occurring at the second sampling rate, an output signal value, said step comprising
- (i) calculating a result according to
- 15 ∑ k = 1 L a k [ F ( t - T k ) - F ( t - T k + 1 ) ] ,
- wherein
- ak is one of the selected plurality of input signal values,
- F(t−Tk) is a first of the plurality of filter response function values, and
- F(t−Tk+1) is a second of the plurality of filter response function values;
- and
- (ii) summing the result with a prior time increment output signal value.
A system for reducing the number of operations required to interpolate a discrete rectangular input signal having a first sampling rate into a discrete output signal having a second sampling rate, the method comprising:
- (a) means for selecting a plurality of input signal values from the input signal, wherein each selected input signal value corresponds to a particular time increment at the first sampling rate;
- and
- (b) means for generating, at a time increment occurring at the second sampling rate, an output signal value, comprising
- (i) means for calculating a result according to
- 16 ∑ k = 1 L a k [ F ( t - T k ) - F ( t - T k + 1 ) ] ,
- wherein
- ak is one of the selected plurality of input signal values,
- F(t−Tk) is a first of the plurality of filter response function values, and
- F(t−Tk+1) is a second of the plurality of filter response function values;
- and
- (ii) means for summing the result with a prior time increment output signal value.
A method of accurately processing a discrete time input signal, p(n), having a first clock rate into a discrete time output signal having a second clock rate, comprising the steps of:
- delta filtering the input signal to produce an intermediate signal having the first clock rate;
- and
- delta interpolating the intermediate signal to produce the output signal;
- whereby computational errors are minimized.
A system for accurately processing a discrete time input signal, p(n), having a first clock rate into a discrete time output signal having a second clock rate, comprising:
- means for delta filtering the input signal to produce an intermediate signal having the first clock rate;
- and
- means for delta interpolating the intermediate signal to produce the output signal;
- whereby computational errors are minimized.
A method of efficiently processing a discrete time input signal, having a plurality of input signal samples that occur at a first clock rate into a discrete time output signal having a second clock rate that is R times the first clock rate, the method comprising the steps of:
- receiving the input signal;
- filtering the input signal with an N-taps finite impulse response (FIR) filter having N filter coefficients according to
- 17 ∑ i = k ceil [ N + 1 - k R ] - 1 b iR - k u ( ( m - i + k ) T s )
- wherein biR−k is one of the N filter coefficients, and u((m−i+k)Ts) is one of the input signal samples.
A system for efficiently processing a discrete time input signal, having a plurality of input signal samples that occur at a first clock rate into a discrete time output signal having a second clock rate that is R times the first clock rate, the method comprising:
- means for receiving the input signal;
- means for filtering the input signal with an N-taps finite impulse response (FIR) filter having N filter coefficients according.to
- 18 ∑ i = k ceil [ N + 1 - k R ] - 1 b iR - k u ( ( m - i + k ) T s )
- wherein biR−k is one of the N filter coefficients, and u((m−i+k)Ts) is one of the input signal samples.
Dependencies are inferred from the claim text.